Biometric techniques have been developed to identify humans based on characteristic physical traits, such as fingerprints and palm prints. For example, palm scanners have been developed that are used to authorize or deny access to buildings, and fingerprint scanners have been developed which are used to access websites and files, or logon to an operating system. These systems employ a dedicated scanner with high resolution imaging capabilities sufficient to obtain a detailed scan of the skin patterns on a finger or palm, thereby enabling identification of the characteristic physical traits in those skin patterns that distinguish one user from another.
There are several barriers to adoption of such biometric techniques on tablet computing devices and touch screen mobile telephones. While dedicated fingerprint and palm scanners have been employed on door access panels and laptop computer housings in the past, for example, where there is sufficient space to mount the scanners, most tablet computing devices and touch screen mobile telephones are compact and do not have sufficient space to mount a dedicated fingerprint scanner or palm scanner. Further, the touch screen technologies used in conventional tablet computing devices and mobile telephones are not of sufficiently high resolution to obtain a usable image of the skin patterns on a fingerprint or palm from which user can be distinguished. As a result, the biometric techniques associated with fingerprint and palm scanning have not been widely adopted for tablet computing devices and touch screen mobile telephones.